According to official regulations, it is obligatory for vehicles that transport goods that they be covered and that the wagon of the vehicle is well covered with canvas to avoid spilling of wastes that could cause problems of dirtiness or toxicity that contaminate the environment and even cause traffic accidents, both on the highways as well as the railroad, etc.
On the other hand, many goods may be affected by the weather conditions during their transport (sun, water, hail, snow, etc.) and thus become damaged if they are not duly protected (grain, fodder, coal, etc.).
At the present,. the canvas used to protect goods is extended and drawn back manually, which forces the drivers and assistants of the vehicles to climb up to the wagon where the goods are transported, with the corresponding risk of accidents due to height and effort to be made apart from entering into direct contact with the material to be transported, which leaves stains and gives off bad smells that become impregnated in their clothes. In the case of trucks, this inconvenience is transmitted to the cab which at times makes it necessary to wear special clothes for certain goods, such as material for asphalting, remains of abattoirs, etc.
This process results in important losses in time. To cover a vehicle with canvas may take between fifteen and twenty-five minutes and to uncover it between ten and twenty minutes, apart from expenses in cleaning sweat shirts, cabs, boots, etc.
At present some vehicles have placed a roller for better arrangement of the canvas or cable to make its movement easier, but in all cases the system is slow, bodily effort is required and still requires that somebody has to climb up to the higher part of the wagon or tank of the vehicle to carry out the canvas covering and uncovering operation.
Among these systems known in the state-of-the-art, firstly the French patent FR-751374 of 1993 can be mentioned. This is a manual system applied to the canvas covering of epoch cars and its purpose is not applicable to the covering of a truck wagon.
Likewise, patent WO 92/05047 of 1992 tries to solve the problem presented of covering the load of a truck by means of a plastic that adapts to the shape of the load. This solution presents problems of a practical nature, such as calculating the height of the mounts to be covered, as in the event that the plastic rubs against any of them to check its advance. Likewise, with this system perfect watertightness is not achieved and water may enter the load although the canvas does not have a water escape outlet.
The invention in question is able to solve all the present problems at the same time as it facilitates that the canvas covering and uncovering operations are carried out automatically. These operations are performed in a time of three to six minutes and the vehicle is left hermetically closed, thus avoiding spills, the time is shortened and, therefore, costs are lowered, as well as eliminating the necessity to climb up to the wagon of the vehicle. At present this necessity causes a high risk of accidents and dirtiness and discomfort in the working conditions of the operators. All these problems have been attested to transport unions and associations, where after a certain period of time the difficulty and risks arising from having to manually cover and uncover canvas are enormously increased.